Frank ii



(No Model.

GOAL SCREEN.

. Patented Mar. 31, 1896.

UNITED STATES PATENT OFFICE.

FRANK II. SYMONS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO HENRY G. JORDAN, OF SAME PLACE.

QOAL-SCREEN.

SPECIFICATION forming part of Letters Patent No. 557,172, dated March 31, 1896.

A li tion filed October 9, 1895. Serial No. 565,125. (No model.)

To all whom it may concern: provided for it, and have secured to said shaft- Be it known that I, FRANK ll. SYMoNs, of cranks 19, two being herein shown, one at each Boston, county of Suffolk, State of Massaend of the shaft,'and the outer ends of said chusetts, have invented an Improvement in cranks are connected by links I) with the 55 5 Coal-Screens, of which the following descripscreen. As the shaft is revolved the screen tion, in connection with the accompanying will be rapidly moved back and forth. By drawings, is a specification, like letters on the providing cranks for thus shaking the screen drawings representing like parts. it will be observed that the screen is at rest This invention has for its object to improve at each time the cranks are upon their dead- 60 the construction of coal-screens, whereby wet centers.

coal may be thoroughly screened and the sieve Screens provided with means for thus shakconstantly prevented from becoming clogged. ing them back and forth are old; but for In accordance with this invention the sieve screening wet coal they are absolutely useless, is suitably supported in inclined position and because the sieve asoon becomes clogged or 6 5 means are provided for moving it bodily back choked, and to obviate this difliculty I have and forth or sidewise quite rapidly, thereby provided means for vibrating the sieve a, shaking it as the coal passes down, and recipwhich, as herein shown, consist of strikers rocating strikers are provided which rapidly adapted to strike the bottom of the sieve or strike or tap the bottom of the sieve, thereby the supporting-rods, two of which are herein 7o vibrating it while it is being shaken. The shown. They are made alike, and each conmeans employed for actuating the strikers is sists of a head 0, suitably capped or otherwise such that they strike a sudden blow, and by protected at the end, which is secured to an their action the sieve is prevented from clogarm 0 pivoted to the frame, as at 0 and the ging. The means employed for shaking the arm 0 has a projection 0 which is acted upon 7 5 sieve consists of a crank motion, and the bya cam 0 which is designed to depress the strikers are operated to tap the bottom of the arm against the stress of a return-spring c sieve when the crank or cranks are substan- The cam c is secured to the shaft 1) and is tially upon their dead-centers, at which time shaped to depress the striker and then perthe sieve is practically at rest, and this is immit it to return instantly by the action of its 80 3o portant in that it prevents undue wear which spring 0 As the striker returns, its head 0 would otherwise occur. strikes the bottom of the sieve aas, for in- Figure 1 shows in perspective a coal-screen stance, it may strike one of the supporting embodying this invention; Fig. 2, a crossrods or bars co -and thereby instantly sets the section of the machine, taken on the dotted sieve in vibration. 85 3 5 line a: as; and Fig. 3, a detail showing the cam As two strikers are provided, I prefer to and crank in the respective positions which actuate them alternately, and hence the actuthey will occupy just before releasing the ating-cams are disposed upon the shaft 1) rehainmer. versely for the accomplishment of this result.

The screen is composed of the sieve a, side To prevent undue wear incident to the 0 pieces a, supporting rods or bars a located heads of the strikers rubbing along the movbeneath the sieve a, and said screen is loosely in g sieve, the parts are so arranged or timed suspended by rods a from any suitable frame that the cams release the strikers when the (not shown) in an inclined position, and the cranks b are upon their dead-centers,the sieve ends of the screen are loosely connected by at such time being practically at rest, and by 5 chains a with a suitable frame (not shown) referring to Fig. 3 such arrangement of parts to prevent too much longitudinal movement. will be seen. The sieve is hence in constant The screen is adapted to be shaken by Vibration while it is being shaken back and moving it back and forth or from side to side forth. rapidly, and to accomplish this result I have I claim- 100 provided a power driving-shaft 5, supported In a coal-screen, the combination of a sieve in an inclined position in suitable bearings loosely suspended in an inclined position, the

rotating shaft 7), crank b thereon, and link b In testimony whereof I have signed my connecting said crank With said sieve, the name to this specification in the presence of IO pivoted spring'actuated striker c, c, and cam two subscribing Witnesses.

a secured to said shaft 1), constructed and ar- 5 ranged to move said striker in opposition to FRANK IT. SYMONS.

its actuatingspring and to release it while Witnesses: the crank is upon its dead-center, snbstan- B. J. NOYEs,

tially as described. F. II. DAVIS. 

